666660631518 has 48 divisors (see below), whose sum is σ = 1651051715040. Its totient is φ = 190442965248.

The previous prime is 666660631451. The next prime is 666660631519. The reversal of 666660631518 is 815136066666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666660631519) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 332746 + ... + 1201682.

It is an arithmetic number, because the mean of its divisors is an integer number (34396910730).

Almost surely, 2^666660631518 is an apocalyptic number.

666660631518 is an abundant number, since it is smaller than the sum of its proper divisors (984391083522).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666660631518 is a wasteful number, since it uses less digits than its factorization.

666660631518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 875041 (or 875038 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 54.

The spelling of 666660631518 in words is "six hundred sixty-six billion, six hundred sixty million, six hundred thirty-one thousand, five hundred eighteen".